1. Field of the Invention
The invention relates to a method and apparatus for automatically testing various properties of a semiconductor device that has a cable.
2. Description of the Related Art
There has been known, as shown in FIG. 13, such a semiconductor device 100 that has a cable connected with it.
The device 100 consists of a device body 104 connected with one end of a cable 102, and a connector 106 connected with the other end of the cable.
The device body 104, receiving a signal through the connector 106 and the cable 102, converts or amplifies the signal and outputs a signal from its terminals 104A.
The device body 104 sometimes receives signals through the terminals 104A and outputs the processed signals from the connector 106. The cable 102 is generally an optical fiber or a conductive wire, and the body 104 has a semiconductor circuit (not shown) for processing the signals.
For inspecting the various properties of the packaged device with a cable, such a method will be applied to as in a general semiconductor device (without a cable) that the terminals 104A of the body 104 are brought into contact with an inspection probe.
FIG. 13 illustrates a testing configuration in which a board-type probe 108 is in contact with the terminals 104A from under the device 100.
FIG. 14 illustrates a testing configuration in which a pin-type probe 110 is in contact with the terminals 104A from over the device 100.
In both cases, input signals are applied from a port 112A of a tester 112 to the device body 104 through the connector 106 and the cable 102, and output signals are sent to a port 112B of the tester 112 through the probe 108 or 110 contacting with the terminals 104A, whereby the tester 112 inspects the properties of the device 100, comparing the input signals with the output ones.
It is also possible to test the device in reversal direction by changing the port 112A with the port 112B.
In order to achieve precise inspection, it is necessary for the device terminals to be in contact with the probe precisely. However, because of fine pitch of the terminals, manual setting between the terminals and the probe sometimes produces erroneous contact, causing incorrect test result.
Therefore, there exists a need to test the semiconductor device automatically.
In order to automate the testing of semiconductor devices, it is required to transport the devices automatically.
Since the semiconductor device has a flexible cable, irregular deformation of the cable easily occurs during transportation, which gives excess stress to the connection point between the device body and the cable. This affects the test result of the device, or sometimes damages the device. Therefore, it has been difficult to automate the transportation and inspection of the semiconductor device connected with a cable.
It is therefore an object of the invention to provide a method and apparatus for automatically testing a semiconductor device with a cable in high precision.
In order to achieve the object mentioned above, the invention provides for an automatic semiconductor device testing apparatus. The device has a cable, a device body connected with one end of the cable, and a connector connected with the other end of the cable. In an apparatus aspect of the invention, the invention includes a tray for holding the device so that the connector can couple to a mating connector directly or indirectly with the device held in the tray; a tray storage capable of storing a plurality of piled trays, having a tray selecting mechanism for supporting a selected tray separated from the adjacent trays, and an ejector for ejecting the tray supported on the selecting mechanism; a transport mechanism for transporting the tray ejected from the tray storage sequentially to an inspection area with the device held in the tray; an inspection connector for automatically coupling to the connector held in the tray at the inspection area; a probe disposed at the inspection area for applying or receiving signals to or from device terminals of the device body, being in contact with or close to each other; an inspection robot for picking up the device body held in the tray and transporting it to the probe to get contact with or close to; a controller to control the inspection robot; and a tester for testing the semiconductor device by applying input signals to one side of the inspection connector or the probe and receiving output signals from the other side.
In this aspect, the tray holds the cable near the device body so that the cable can be set along a connecting direction of the device body, and guided in the connecting direction when the device body is removed from or restored into the tray.
Preferably, the apparatus may further include a pressing mechanism for pressing the terminals on the probe in a state that the device body is in contact with or close to the probe.
In a particular arrangement, the apparatus further includes a device body imaging device for imaging the posture of the device body retained on the inspection robot. The controller has a reference posture storing section for storing a reference retained posture, and a posture error calculating section for calculating an error between the reference posture and the retained posture imaged by the device body imaging device, and controls the inspection robot to transport the device body onto the probe together with correction of the calculated error.
In another aspect of the invention, the apparatus has a tray transfer device for holding and transferring the tray. The controller controls both of the tray transfer device and the inspection robot in synchronism with each other, so that the device body can be transported from the imaged position by the imaging device to the probe with the relative position between the device body and the cable maintained.
Preferably, the tray transfer device may be a rotation table to hold and rotatably transfer the tray, and the device body imaging device and the probe are arranged along an arced locus concentric with the table. The controller controls the inspection robot so that the device body can rotatably move along the arced locus from the imaging device to the probe.
Further, the rotation table can hold a plurality of trays.
In yet another aspect of the invention, the apparatus may include a probe imaging device for detecting a probe set position. The controller has a reference position storing section for storing a reference set position of the probe, and a position error calculating section for calculating an error between the reference set position and the probe set position detected by the probe imaging device, and controls the inspection robot so as to transport the device body onto the probe with the set position error corrected.
Particularly, the probe imaging device can detect the position of the device terminals brought into contact with or close to the probe. The controller has a displacement calculating section for calculating the displacement between the probe and the terminals based on the probe set position and the position of the terminals, and an allowable value storing section for storing a given allowable displacement value. The controller controls the inspection robot so that the device body can get into contact with or close to the probe with the displacement corrected if the calculated displacement is over the allowable value.
In still another aspect, the apparatus is provided with a front-end system and a front-end robot. The system executes a heat-retaining process for keeping the device body in a given temperature, a dust removing process for removing foreign substance from the device body, and an electrostatic discharge process for discharging static electricity from the device body. The front-end robot picks up the device body held on the tray, and transfers it to the front-end system.
In a particular embodiment, the inspection robot can also serve as the front-end robot.
In further aspect of the invention, the transport mechanism is capable of transporting back a tray, which holds the inspected device, to the tray storage, and has an unloader for unloading the returned tray into an open space in the tray selecting mechanism.
In a method aspect of the invention, the apparatus includes the following steps: holding a semiconductor device in a tray, the device having a cable, a device body connected with one end of the cable, and a connector connected with the other end of the cable, so that the connector can couple to a mating connector directly or indirectly; storing a plurality of the trays in a tray storage; selecting a certain tray from the tray storage; transporting the selected tray sequentially to an inspection area with the device held in the tray; coupling automatically an inspection connector to the connector held in the tray at the inspection area; bringing the device body into contact with or close to a probe; testing the device automatically and continuously by applying input signals to one side of the inspection connector or the probe and receiving output signals from the other side; and returning the tray after the test into the tray storage on its expected step position.
According to the invention, a semiconductor device connected with a cable can be examined automatically.